Safety barriers that are used to divide or separate highway vehicle lanes are a common sight along the various interstates and other freeways, particularly at construction sites. The barriers are sometimes used as temporary lane designators and typically separate two or more lanes of traffic traveling in opposite directions. Such barriers generally serve as permanent safety barriers in lieu of guard rails and similar structures.
These highway safety barriers are typically made of concrete or similar materials. Each barrier is generally trapezoidal in transverse section, and typically has a height of a few feet and may be six or more feet in length. The barriers also may be a foot or more wide. Of course, the exact size and shape of each barrier may vary depending on the particular use and design.
The safety barriers are commonly laid end to end along a stretch of a road requiring lane separation. Most of the barriers used at a particular site will usually be of a uniform length. However, it is not unusual for the standard barrier length to be unworkable in some situations, such as near the ends of a job site, around curves, or near bridge abutments and similar obstructions. In such cases, it is often desirable to have a barrier with a shorter than standard length. Also, many of the safety barriers utilized today are cast in whole or part as a single continuous or integral length. In order to allow such continuous cast barrier to properly expand and contract as a result of exposure to the elements, it is necessary to cut such barriers at regular intervals. Generally, it is desirable to form a cross-wise cut in the barrier without cutting the barrier all the way through.
A common device used to cut concrete pavement is a flat saw. A flat saw is typically used to form grooves in concrete. Such saws are used to assist in the removal of concrete by first cutting the concrete into sections and then breaking such sections up into smaller pieces. The flat saw usually includes a large circular saw blade driven by a four cylinder gasoline engine. The circular saw blade includes a large number of teeth or cutting bits on the outer perimeter of the wheel to cut the concrete. An example of a large portable flat saw is a Series CC6500 flat saw sold under the trademark CORE CUT by Diamond Products, Inc. of Elyria, Ohio. An example of a small portable flat saw is disclosed in Jedick U.S. Pat. No. 4,840,431 which is owned by Diamond Products, Inc. It is known that at some construction sites, persons have attempted to cut concrete safety barriers with such flat saws.
Efforts to use a flat saw to cut concrete barriers create problems because the flat saw is not designed or intended for cutting elevated surfaces or for cutting through relatively thick sections of concrete. For example, when only a partial cut is to be made, the flat saw leaves a curved groove at the bottom of the cut which may be unacceptable. Also, as the flat saw cuts through a barrier, friction increases substantially between the barrier and sides of the circular saw blade making the saw difficult to control and producing high frictional heat that dramatically wears the circular saw blade. Positioning of the flat saw is also difficult because the initial cutting surface is usually elevated above the normal cutting surface for such a saw. The flat saw may weigh 1300 pounds or more which increases the difficulty of raising the saw sufficiently to cut a barrier.
The prior art also provides other types of saws that could be used for cutting concrete barriers but they present some distinct disadvantages. Specifically, diamond wire saws are commonly employed in stone quarries. Such wire saws comprise separately a hydraulic pump, a main drive wheel powered by a hydraulic motor, and one or more idler wheels. An example of such a wire saw is a wire saw Series WS25 sold under the trademark CORE CUT by Diamond Products, Inc. Such wire saws are generally not suitable for cutting concrete barriers since they comprise multiple separate and distinct pieces and they require significant amounts of time to set up.
The prior art does provide very large wire saws for cutting concrete barriers. An example of such a saw is a wire saw sold by the W. F. Meyers Company, Inc. of 1017 14th Street, Bedford, Ind. This wire saw which weighs about 5,000 pounds is designed to be mounted on the bed of a truck or trailer. Unfortunately, this wire saw is quite large and costly.
Thus, there is a need for a portable and compact apparatus that can be used to cut and shape large concrete barriers at construction sites and other locations as well.